title: Fibronectin extra domain A (EDA) sustains CD133(+)/CD44(+) subpopulation of colorectal cancer cells.
abstract: Fibronectin is a major extracellular matrix glycoprotein with several alternatively spliced variants, including extra domain A (EDA), which was demonstrated to promote tumorigenesis via stimulating angiogenesis and lymphangiogenesis. Given that CD133(+)/CD44(+) cancer cells are critical in tumorigenesis of colorectal cancer (CRC), we hypothesize that fibronectin EDA may promote tumorigenesis by sustaining the properties of CD133(+)/CD44(+) colon cancer cells. We found that tumor tissue and serum EDA levels are substantially higher in advanced versus early stage human CRC. Additionally we showed that tumor tissue EDA levels are positively correlated with differentiation status and chemoresistance, and correlated with a poor prognosis of CRC patients. We also showed that in colon cancer cells SW480, CD133(+)/CD44(+) versus CD133(-)/CD44(-) cells express significantly elevated EDA receptor integrin α9β1. Silencing EDA in SW480 cells reduces spheroid formation and cells positive for CD133 or CD44, which is associated with reduced expressions of embryonic stem cell markers and increased expressions of differentiation markers. Blocking integrin α9β1 function strongly reversed the effect of EDA overexpression. We also provided evidence suggesting that EDA sustains Wnt/β-catenin signaling activity via activating integrin/FAK/ERK pathway. In xenograft models, EDA-silenced SW480 cells exhibit reduced tumorigenic and metastatic capacity. In conclusion, EDA is essential for the maintenance of the properties of CD133(+)/CD44(+) colon cancer cells.
authors.affiliation: Department of Oncology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Ou
authors.forename: Jia
authors.initials: J
authors.lastname: Deng
authors.forename: Xing
authors.initials: X
authors.lastname: Wei
authors.forename: Ganfeng
authors.initials: G
authors.lastname: Xie
authors.forename: Rongbin
authors.initials: R
authors.lastname: Zhou
authors.forename: Liqing
authors.initials: L
authors.lastname: Yu
authors.forename: Houjie
authors.initials: H
authors.lastname: Liang
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005353:Fibronectins / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D007150:Immunohistochemistry; D016023:Integrins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000378:metabolism*
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D005353:Fibronectins; D006023:Glycoproteins; D018960:Hyaluronan Receptors; D016023:Integrins; C000606023:PROM1 protein, human; D010455:Peptides; C113256:integrin alpha 9 beta 1